Mineral castor oil



Patented Jan. 4, 1949 unirte Hamme d `12 claims.

, mainframes ib-seaweed Hyde- `cabrrl oils land to the'i'ethodofpreparing the saine,r andmore particularly relates to improved 'mineral"castor foils.

f 1scr-{carniclK minerai easter ons are `hyd`mci`rbcs-n oils, `lsuch as'petroleum `oil's 'containing 'dissolved orjdisperjsed therein faAloasiefalux'rlinum soap of `"a mener-fatty and, such as oleic"aiqstearic acid, `IJ'almitc acid, beieiiic acid, etc. The fini-'neralcastor" oils, sometimes referred to as `-'castor"ina ciliineoils, areoils identied in the trade by their lng" yisoosities and are used mainlyas lubricntsbfin equipment where high temperatures are not encountered.The viscosities of such oils `range vfr orn about *,100secondsH-Sayboltl Uniyer'sfal grt-100 "EL lto about T000 secondsorfhigh'er at 210 These oils, characterized by their stringinsa areused` "primarily `for the lubrication 'of "bearings, differentials, andother iiriiiriigf l"iefrt`-5s of machinery `Where it is desirable toemploy oils of l'iigh stability.` I n order `t'o 'stabilize "Vriiral'c'as- :tdrloil's "against separation, `a small quantity of polyhydriolalcohol 'is "incorporated 'in tl'ie edm"- "position A naaste-n mme@arnese 'gaap filigree@ ietolfntneinventionisfto provide meinen of"-fpreparing "an '-irripryed mineral castor "oil whichi'sjnotjrubberyand cohesive and tvh'ichfposse improved flowcharact'eristios.k Other objectsai'id advantages of the Ipresentinvert-tid Will'become apparent from 'the following descr :on tlie'reof.

We have ydiscoyered that the foregoing 'objects can be attained byincorporating in mineral cas- `tor oils, particularly those containing apolyhydric alcohol, a small amount of a metal soap of a preferentiallyoil-:soluble sulfonic acid. The preferentially oil-soluble sulfonicacids employed in accordance with the present invention are preferablythose :obtained in the treatment of hydrocarbon oils, such as mineral orpetroleum oils with strong, i. e. concentrated or fuming,

sulfuric acid. However, for the rpurpose hereindescribed, ,We can useother preferentially "oilsoluble sulf'or'io acids, such "fas `those"obtained by the sulfntiqnlofoienn polymers nayingfat Vleast but 22carbon *atofmysin the molecule or lsul- 'i'ally toil-solubile siref'ably the *alkali h so 15's ffeiionisii-Boi; t-lie isbdiurn, lpetal'barium soaps thereof. y amount of the sulfonate, sufficient `toifnpatrto the mineral castor oil non-rubbery and non-c0- hesiye`properties need be employed, usually from about 0.005% ito about 2.0% byweight, and preferably from 'about'0;01`% to about 1% by Weight of the`sul`for`1`ate is suicient. However, depending upon the aluminum soapcontent of the base 'and the viscsit'yof the oil used, smallerrlarg'ramounts of thesulfonate can be eifiploye'd. i

The preferentially oil-soluble sulfonates employed in the presentinvention are sutably'those 20 'btaii'ie'ilf Tin thetratnt 'di lviscous'petroleum l "ated and/l "fu Ing sulfur'ic @acid the treatmentcoilrietrole iio'ils with strong; i,` e. `funding 'or icnitrat ulfricacid, 'tiro genral typsf s'iilfonic :ac s ie obtained; those which arepreferentially oluble l*and recovered-from the iacid sliidgelayer, andthose prefere'itiallyl oil-'soluble "and "robot/ered lprincipally 4"fromthe oil layer. `-Depending 'upon the cnditiosof separation, smallamounts ofpref'- erentially oil-soluble sulionic acids are recoverablefron the v'acid sludge layer. The *sulfonic 'aoidsfaji'e recovered byeiitacting theaci'ddteated oil Witli about 60% alcohol, v"or "thes'ulfo'riic Vacids in tl'i'eoilZlayer can be neutralized and `the soapsvrecoye'red l from `the oil by ie'irtr'a'ction with alcohol. frireextracreufsuiforiie eres Y' suifonates can te further purified byfurther er; aerien with. alec- "hol ofbit'80% `s r gth. T li'esepreferentially o" "olubl'elfo'nic Ifacid's or the soapsl thereof, "bcase of their characteristic "reddish-brown totliepet'rolem the acidsludge, with 60% alcohol. The crude sulfonic acid obtained can befurther extracted with 80% alcohol to obtain a purified mahogany acid.The alkaline earth soaps, for example the calcium soap of such purifiedmahogany acids, which have a molecular weight of about 430, areespecially well suited for use in accordance with the present invention.

Another suitable sulfonate found to be well suited for the presentinvention is the alkali metal, such as sodium soap of preferentiallyoil-soluble mahogany acids having a molecular weight of in the range ofabout 470-500.

The addition of such sulfonates to mineral castor oils of the typeherein-described lowers the viscosity of the product and in additionproduces a change in structure, whereby the rubbery and cohesivecharacteristics of conventional mineral castor oils are modied so that astringy adhesive structure is obtained. While the present invention isapplicable to improve the properties of mineral castor oils in general,it is particularly effective in compounded mineral castor oils`cornprising aluminum soap, a small proportion of a polyh-ydric alcohol,and a major proportion of petroleum oil. Mineral castor oils having thefollowing compositions in the following approximate proportions areillustrative of preferred embodiments of the invention:

1 Weight percentages.

The polyhydricalcohols employed in the preparation of the mineralcastor'oil include glycerine, ethylene glycol, diethylene glycol andpropylene glycol. Other polyglycols or polygycerols, including thederivatives of polyhydric alcohols, may also be employed.

Any hydrocarbon oil ofl suitable viscosity can be used; usually mineraloils ranging in viscosity from about 70 seconds Saybolt Universal at 100F. to about 210 seconds at 210 F. can be employed.

The mineral castor oil improved by the hereindescribed invention may beprepared from the aluminum soap of fat or fatty acids which has beenprepared by the double decomposition method, or it may be prepared froma soap made by direct saponication of a fatty acid with aluminumhydroxide, which is available in a reactive form known as gelatinousalumina. As noted above, the fat or fatty acids are the higher molecularweight fat or fatty acids, such as oleic acid, stearic acid, palmiticacid, behenic acid, or commercial so-called animal fatty acids composedmainly of stearic, palmitic and oleic fatty acids. The following exampleillustrates a method of preparing a mineral castor oil of theherein-deto a mixer and the contents then agitated or stirred until asmooth paste is obtained. The paste is then heated to about 250-275 F.and maintained at this temperature until the soap is completelydissolved in the oil. If necessary, additional oil is graded in to lowerthe consistency of the base. When the soap is uniform and smooth, thebalance of the oil is added rapidly, while regulating the temperature sothat the batch nishes at a temperature of .l80220 F.

The present invention is not limited to mineral castor oils prepared bythe above method, but is applicable to mineral castor oils prepared byother methods, such as for example mineral castor oils prepared by themethod described in U. S. Patents 1,691,654 and 2,031,405. The mineralcastor oil can also be prepared by a two-step method in which the firststep comprises the manufacture of a base approximately 30 to 50%aluminum soap and the second step comprises compounding of the base withpetroleum oil, and small amounts of the polyhydric alcohol and theoil-soluble sulfonate.

The effect of the oil-soluble sulfonate on the structure of the mineralcastor oil is illustrated `by the following data using as the control amineral castor oil containing 5% aluminum stearate, 1% glycerin, and 94%of a petroleum oil having a Saybolt Universal viscosity at 100 F. of 80to 85 seconds.

V.Asphalt Viscosity seconds A Control ---i 737 p Control-|-0.05% calciummahogany soap 1 246 C0ntrol+0.05% sodium mahogany soap2 204 1 Molecularweight of acid-approximately 430. 2 Molecular weight ofacid--approximately 470-500.

The effect of adding the mahogany soap is not merely one of loweringtheV viscosity since this could readily be accomplished by a decrease inthe percentage of aluminum stearate; the addition of the oil-solublesulfonate is necessary to obtain the desired structural effect. Whilethe alkali metal or alkaline earth' soaps of preferentially oil-solublesulfonic acids can be used, we prefer to use the alkaline earth soaps ofsuch sulfonic acidssince they lower the viscosity of the product to alesser degree than do the alkali metal soaps of the sulfonic acids. Thecalcium soaps of mahogany acids having a molecular weight in the rangeof about 400 to 450 are preferred.

Mineral castor oils of the present invention have much improvedstability properties as illustrated by the data inthe following table.The controlused was a mineral castor oil comprising 5.0% aluminumstearate, 1.0% glycerine, and 95.0% petroleum oil having a SayboltUniversal viscosity at F. of 80-85 seconds.

Asphalt Viscosity at 100 I".

Samples any Soap The slight decrease in viscosity'of sample B upon agingis much more desirable andpreferable to the large increase in viscosityof sample A.

The ,following examples are illustrative of the two grades of mineralcastor oils prepared in accordance with the present invention:

The percentages given herein and in the apN pended claims are Weightpercentages unless otherwise specied.

The term asphalt viscosity is thevscosity at 100 F. obtained on aSaybolt Viscometer using the sc-called asphalt tip.

It is to be understood that the foregoing references to preferredembodiments of our invention are not to be considered as limiting butmerely as illustrative o the generic invention and that many variationsmay be made Within the scope of the appended claims.

We claim:

1. A mineral castor oil comprising a major proportion of a hydrocarbonoil, from about 0.5% to about 15% of an aluminum soap, from about 0.05%to about of a polyhydric alcohol, and from about 0.005% to about 2% of ametal soap of a preferentially oil-soluble sulfonic acid.

2. A mineral castor oil comprising a major proportion of a hydrocarbonoil, from about 0.5% to about of an aluminum soap, from about 0.05% toabout 5% of a polyhydric alcohol, and from about 0.005% to about 2% ofan alkaline earth soap of a preferentially oilsoluble sulfonic acidderived from the treatment of petroleum oils with strong sulfuric acid.

3. A mineral castor oil as described in claim 2 in which the alkalineearth soap of the preferentially oil-soluble sulfonic acid is thecalcium salt.

4. A mineral castor oil comprising a major proportion of a hydrocarbonoil, from about 0.5% to about 15% of an aluminum soap, from about 0.05%to about 5% of a polyhydric alcohol, and from about 0.005% to about 2%of an alkali metal soap of a preferentially oil-soluble sulfonic'acidderived from the treatment of petroleum oils with strong sulfuric acid.

5. A mineral castor oil described in claim 4 in Which the alkali metalis sodium.

6. A mineral castor oil comprising a major proportion of a hydrocarbonoil from about 1% to about 12% of an aluminum soap, from about 0.25% toabout 3% of a polyhydric alcohol and from about 0.025% -to about 1% ofan alkali metal soap of a preferentially oil-soluble sulfonic acid.

'7. A mineral castor oil described in claim 6 in which the polyhydricalcohol is glycerin and the alkali metal soap is a sodium soap.

8. A mineral castor oil described in claim 7 in which the polyhydricalcohol is glycerin and the alkaline earth soap is a calcium soap.

9. A mineral castor cil comprising a major proportion of a hydrocarbonoil, from about 1% to about 12% of aluminum stearato, from 0.25 to about3% glycerin and from about 0.025% to about 1% of a calcium soap of amahogany acid having a molecular Weight of from about 400 to about 450.

10. A mineral castor oil comprising, a major proportion of a hydrocarbonoil, from about 1% to about 12% aluminum stearate, from about 0.25% toabout 3% glycerin and from about 0.025% to about 1% of a sodium soap ofa mahogany acid having a molecular weight of from about 470 to about500.

11. A mineral castor oil comprising a major proportion of a petroleumoil, from 2.5% to about 7% aluminum stearato, from 0.5% to about 1.4%glycerin, and from 0.05% to about 0.2% calcium mahogany soap.

12. A mineral castor oil comprising a major proportion of a hydrocarbonoil, from about 1 per cent to about l2 per cent of an aluminum soap,from about 0.25 per cent to about 3 percent of a polyhydric alcohol andfrom about 0.025 per cent to about 1 per cent of an alkaline earth soapof a preferentially loil-soluble sulfonic acid.

REUBEN A. SWENSON. ALFRED W. W'EITKAMP.

REFERENCES CITED The following references are of record in the nie ofthis patent:

UNITED STATES PATENTS Number Name Date 2,031,405 Blount Feb. 18, 19362,308,116 Silverman Jan. 12, 1943 2,394,790 Liehe Feb. 12, 1946

